app.js

const express = require("express");
const bodyParser = require("body-parser");
const ejs = require("ejs");
const mongoose = require("mongoose");
const _ = require("lodash");

const app = express();
//var urlencodedparser = body-parser.urlencoded({extended:true});
app.set('view engine','ejs');
app.use(bodyParser.urlencoded({extended:true}));
app.use(express.static("public"));
//var Items=[];
mongoose.connect("mongodb+srv://admin-shreyash:Shreyash@123@cluster0.1t8zl.mongodb.net/todolistDB?retryWrites=true&w=majority",{useNewUrlParser:true});

const itemsSchema = {
	name:String
};

const Item = mongoose.model("Item", itemsSchema);

const item1 = new Item({
	name: "Welcome to Your todoList!"
});

const item2 = new Item({
	name: "Hit the + button to add a new item"
});

const item3 = new Item({
	name:"<-- Hit this to delete an Item."
});

const defaultItems = [item1,item2,item3];

const listSchema = {
	name:String,
	items:[itemsSchema]
};

const List = mongoose.model("List",listSchema);

app.get("/" , function(req,res){

	Item.find({},function(err,foundItems){
		if(foundItems.length===0){
			Item.insertMany(defaultItems,function(err){
				if(err){
					console.log(err);
				}
				else{
					console.log("Succesfully Saved default items");
				}
			});
			res.redirect("/");
		}
		else{
			res.render("list" , {listTitle:"Today" , newListItems:foundItems});
		}
		
	});
	
});

app.get("/:customListName",function(req,res){
	const customListName = _.capitalize(req.params.customListName);
	List.findOne({name:customListName},function(err,foundList){
		if(!err){
			if(!foundList){
				//create a new List
				const list =new List({
					name:customListName,
					items: defaultItems
					});
				list.save();
				res.redirect("/" + customListName);
			}
			else{
				//Show an existing List
				res.render("list",{listTitle:customListName,newListItems:foundList.items});
			}
		}
	});
	
});

app.post("/",function(req,res){
	var itemName = req.body.newItem;
	const listName = req.body.list;
	const item = new Item({
		name:itemName
	});

	if (listName === "Today"){
		item.save();
		res.redirect("/");
	}
	else
	{
		List.findOne({name:listName},function(err,foundlist){
			foundlist.items.push(item);
			foundlist.save();
			res.redirect("/" + listName);
		});
	}	
});

app.post("/delete",function(req,res){
	const checkedItemId = req.body.checkbox;
	const listName = req.body.listName;

	if(listName === "Today")
	{
		Item.findByIdAndRemove(checkedItemId,function(err){
		if(!err){
			console.log("Sucessfully deleated checked item");
			res.redirect("/");
		}
		})
	}
	else
	{
		List.findOneAndUpdate({name:listName},{$pull:{items:{_id:checkedItemId}}},function(err,foundList){
			if(!err)
			{
				res.redirect("/" + listName);
			}
		});
	}
	
});


app.listen(process.env.PORT || 3000,function(){
	console.log("Server is running on port 3000");
});